The proposed project is to develop an instrument for cell biology research based on a technique for perturbing local cytosolic concentrations of key signal transduction mediators with sustainable submicrometer resolution. In this technique, microspheres are decorated with selected enzymes, creating high local concentrations of an effector at the particle surface. Laser tweezers are used to manipulate these particles in a cell. The Phase I project will prove the feasibility of implementing the optical trapping system based on waveform modulation and demonstrate the effectiveness of the technique using a relatively low-cost diode laser in place of the titanium sapphire laser used in preliminary work. Successful application of the technology will have broad implications. Most importantly, it would provide a means for effecting local cytosolic properties over timescales much greater (e.g., hours) than cell biologists currently are able to achieve using techniques such as focal uncaging and electrophysiological techniques, both of which typically result in broad cellular distribution of effectors within milliseconds to seconds due to diffusion. The proposed instrument will provide the capability to directly deliver a biochemical, pharmacophore or protein of choice to any site within a cell and thereby constitutes a tremendous technological advance for the biomedical research field.